Method of obtaining oxid fumes from ores and furnace products.



UNITED STATES PATENT OFFICE.

HERMANN PAPE, OF HAMBURG, GERMANY.

METHOD OF OBTAINING OXID FUMES FROM DRES AND FURNACE PRODUCTS.

Patented Jan. 21, 1908.

Application filed December 31.1906. Serial No. 350.312.

' the presence of oxygen, or which volatilize as metallic vapor and then burn again to oxids in the current of air, may be separated from ores or furnace products by mixing the latter with carbon, and conducting a stream of flames or current of air through the mixture which brings the carbon to moandescence, so that the temperature of reduction ofthe metal contained in the ores is attained, said stream of flames or current of air simultaneously containing excess oxygen,

so that the oxidation of thereduced metal may be efie'cted. In this lead, among other metals, from their oxygen' compounds, or from their carbonic acid or sulfur com ounds. In the case of zinc, for example t e arrangement has been such that a 'mixture' of ore with carbon has been placed on a long flat ate, air having been assed through the c arge by means of a b ast.- The charge became manner zinc and may be separated incandescent very soon, and zinc oxid vapors were developed which were led away with the furnace gases and were collected in sackfilters after they had cooled down. The furnaces referred to work periodically, being charged afresh from time to time, a blast being sent through the charge until the removal of the zinc is com leted. The term erature is maintained so high that as granu ar a mass 'as possible and one which is as little sintered together as possible is left behind as aresidue,

which mass is withdrawn from the furnace after the charge is Worked up. This method may be employed for certain ores particularl for American franklinite; but if the ore sinters, however, or shows atendency to melt, the above described method of working cannot be employed, as much too great quantities of zinc are then left behind in the residue.

In contradistinction to the above de- 'plo'yed.

the present invention is such that every kind of zinc ore for example, or zinkiferous furnace-products may be worked up with success, and also. in a continuous process. Forms of furnaces ma be employed such as those which have a eady' been used for similar purposes. The ore which is. re-.

ared in the manner as further descrl ed ereafter is introduced at an admission place into the furnaces, while the liquid dross which is formed may be continuousl removed at suitable places from the ower parts of the. furnace.

The new method in accordance with the present invention is a combination of various operations w 'ch in part have become known in some details, which operations are connected in such a manner that ,a combined effect which has hitherto not been at tained is produced. The ield according to the present method is sue a favorable one that zinkiferous materials, for example may forms.

The disintegration of the ore or of the furnace-products is sufficiently fine and they are sufficiently intimately mixed with carbon in order to efiect the separation of the separate grains of ore from one another with certainty by means of grains of carbon. situated between them. t is true that in certain cases'a fine disintegration and an intimate mixing of the materials has been found preferable hitherto for charging the muflles of furnaces for zinc distillatlon, but for furnaces, however, in which the reduction of zinc is eifected by em loying a current of air which is ser tthroug .the charge, the fine disintegratioiiipf the ore with intimate mixing of thereducing means which is likewise finely disintegrated. has not yet been em- Accordin to the method of the present invention the material is chosen of such a granular size that at least 50 of the materials are less than mm. in diameter. Such grains are mixed with carbon in such a manscribed method, the method according to 1 ner that it may be taken that on an average cent carbon in the process of reduction.

zone. At the high After the raw material has been mixed with the carbon or similar means of reduc-v tion, any possibly necessar additions, such as lime, sand or the like W ich are likewise suitablydisintegrated are added to the mixture, and lastly an agglutinantyis added, if the mixture in itself is not, say, in a condition to become sufficiently hard after it has been pressed together. As agglutinant, lime, cement, disintegrated coal-tar pitch, etc for example, may be taken, the latter, say, in the condition in which it is employed in making briquets from small coal.

After the charge has been ground and mixed in the above-described manner, the same is-molded into briquets by-means of a press in known manner. Also the charge may be placed in a suitable sintering furnace in the condition which is desired for the workin of the furnace. The prepared charge 1s then further worked up in a furnace which is continuously charged from above. 'A powerful current of air is passed-through the charge, it may be by means of a blast, it may be by suction, and is regulated in such a manner that the charge is heated to at least a red glow up to its upper surface. 'l'he formation of tutty in t e charge itself is thereby avoided. The briquets which are newly thrown on to the charge catch fire and glow on the upper surface, and the metallic vapors which rise up from the lower part of the charge burn to oxids at the u per surface of the charge. Air is preferab y admitted in the melting zone in which there must be incandescence when working up zinc ores, and a quantity of coke in 1pieces-or lumps is .added to the charge, so t at the necessary temperature is certainly maintained in the melting zone. When the bri uets arrive in the melting zone in an alrea y semi-plastic state, the zinc compounds which are in the briquets in direct contact with carbon are decomposed,'and the zinc vapors which form urn to zinc oxid a ain above the melting al temperature which characterizes the new process, a simple sintering together of the grains of ore from which the zinc is removed is prevented from taking place, and the same always become molten. By the separate -melted grains flowin together, dross is finally formed which 1s blown out from the lower part of the furnace in the usual manner.

The heat of the gases of combustion which carry away the volatile metallic oxids which are formed in the furnace may be cmployed in suitable manner, for example for ores, or for heating steam b'ollers.

ldetals which are reduced by carbon, but

'liquid'state from the furnace.

iferous reducing means therewith, in making briquets of the mixture thus obtained, in feeding said briquets continuously into a furnace, in burning the carbon contained in said briquets in said furnace, in continuously supplying a powerful current of air to said burning briquets, whereby the volatile metals contained in said ore or furnace products are first reduced and then burned to oxids in the excess oxygen of the current of air,l"in, con tinuously withdrawing said oxids withfjjthe' furnace gases and in continuously removing thenon-volatile residue of'said briquets in a 2 A method of obtaining oxid fumes from ores or furnace products, consisting in finely disintegrating said ore or furnace prod;-

ucts, 1n mixing finely disintegrated carbon therewith, in making briquets of the mixture thus obtained, in feeding said briquets continuously into a furnace; in burning the car bon contained in said briquets in said furnace,- in continuously supplying a powerful current of air to said burmng briq uets, whereby the volatile metals contained in said ore or furnace roducts are first reduced and then burned to oxids in the excess oxygen of the current of air, in continuously withdrawing said oxids with the furnace gases and in continuously removing the non-volatile residue of said briquets in a liquid state from the furnace, the quantity of carbon which is added to said core or furnace prod ucts being sufficiently great that in'the combustion of the carbon the necessary amount of heat is obtained not only for the reduction and vaporization of the metal in said ore or furnace product, but also for melting the residue of the latter.

3. A method of obtaining oxid fumes from ores or furnace products,consisting in, finely disintegrating said ore or furnace products, in mixing finely disintegrated carbon therewith, said disintegration of said ore or furnace products being sufficiently fine and the mixing with the carbon sufficiently 'intimate in order to effect with certainty a separation of the separate grains of ore one from anotherby means of intermediate grains of carbon, in making briquets of the mixture thus obtained, in feeding said briquets continuously into a furnace, in burning the carbon contained in said briquets in said furnace, in continuously supplying a powerful by the volatile metals contained in said'ore or furnace products are first reduced and then burned to oxids in .the excess oxygen of the current of air, incontinuously withdrawing said oxids with the furnace gases and in continuously removing the non-volatile residue of said briquets in a liquid state from the furnace. v

4. A method of obtaining oxid fumes from ores or furnace products, consisting in finely disintegrating said ore or furnace product, in mixing finely disintegrated carboniferous reducing means therewith, in making briquets of the mixture thus obtained, in feeding said briquets continuously into a furnace, in adding carbon to said briquets in said furnace, in burning said carbon and the carbon'contained 1n saldbriquets 1n said furnace, in continuously supplying a blast of air to said burning briquets, whereby the volatile metals contained in said ore. or furnace product are first reduced and then burned to oxids in the excess oxygen of the current of air, in continuously withdrawing said oxids with the furnace gases and in continuously removing .the non-volatile residue of said briquets in a liquidstate from the furnace.

In testimony whereof I have signed my name to this specification in the presence of the two subscrlbing witnesses.

HERMANN PAPE. Witnesses ERNEST H. L. MUMMENHOFF, O'r'ro W. HELIMRICH. 

